I don't believe that Major Looscan ever commanded Hawpe's 31st Texas. From "Polignac's Texas Brigade" by Alwyn Barr, I see references to Lt Col Guess often commanding the regiment, which was sometimes referred to as Guess's battalion [probably since the regiment only had 9 companies].

"Speight's brigade camped near Ft Smith on Jan 15, 1863....here there also occurred a seemingly temporary change of command for the 31st Texas, when Col Hawpe left the regiment under Lt Col Guess while he returned to Dallas. The change proved to be permanent, however, for Hawpe never returned to his command, apparently for business reasons. "

[Fall 1863 in Louisiana]-"..it had been a trying period for the brigade...and Speight's arrest of Lt Col Guess on charges of trading with the enemy."

[late Sept-battle of Stirling Plantation]-"...The 31st Texas had 1 killed, 12 wounded and 4 missing. Lt Col Guess, who had accompanied the regiment into action although under arrest, was captured while attending to the wounded."...The 31st Texas commanded by Major Frederick Malone..”

Footnotes for June 1864 in this book, cite letters from George Guess indicating that perhaps he was once again present, although no indication he was in command

Official Records Vol XL!, Pt 3, p. 967 show the 9/30/64 organization of the Army of the Trans Miss Dept, and Major Malone is listed as the commanding officer of the 31st Texas.